Rheological characterisation of aqueous extracts of triticale grains and its relation to dietary fibre characteristics

Rheological properties of triticale extract are important determinants of the grain utility. Extracts of eight triticale cultivars and a wheat reference grown at two different locations i.e. Svalöv and Kölbäck were analysed for their viscoelastic properties. Extracts of triticale cultivars grown at Svalöv were significantly higher in elastic modulus (average 9.0 Pa), viscous modulus (average 12.7 Pa) and complex modulus (average 15.6 Pa) at 2.1 Hz than those grown at Kölbäck (average 3.1, 5.6 and 6.4 Pa, respectively). However phase angle was not affected by location, and all triticale extracts had phase angle >45°. Large inter-cultivar variation was also observed in viscoelastic properties of triticale extracts. Some of the triticale cultivars grown at Kölbäck (Dinaro, Cando, Talentro, and DED 145/02) and Svalöv (DED 145/02) were similar to wheat in their complex modulus values. When evaluating the contribution of arabinoxylan (AX) and β-glucan to rheological properties of triticale extracts by partial least square (PLS) regression, it was evident that β-glucan had little role and most of the contribution to viscoelastic properties came from AX. AX fine structure was more important in explaining variation in complex modulus of triticale extract than content and extractability, or molecular size.

► Rheological properties of triticale extracts are studied in this article.
► Significant effect of location on triticale extract rheology was observed.
►  Extract rheology was correlated with the content, molecular size and structure of arabinoxylan.
► Arabinoxylan structure contributed more towards rheology than its content or molecular size.
► β-Glucan had little contribution towards rheology of triticale extracts.